From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp51.i.mail.ru (smtp51.i.mail.ru [94.100.177.111]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dev.tarantool.org (Postfix) with ESMTPS id A1FDF469719 for ; Tue, 13 Oct 2020 17:08:35 +0300 (MSK) Date: Tue, 13 Oct 2020 14:08:34 +0000 From: Nikita Pettik Message-ID: <20201013140833.GA18852@tarantool.org> References: <5c615731b1bd3e6d279dfb0cbc92823dea993a03.1602413265.git.imeevma@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <5c615731b1bd3e6d279dfb0cbc92823dea993a03.1602413265.git.imeevma@gmail.com> Subject: Re: [Tarantool-patches] [PATCH v3 1/1] sql: enable autoindex optimization List-Id: Tarantool development patches List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: imeevma@tarantool.org Cc: Mergen Imeev , tarantool-patches@dev.tarantool.org On 11 Oct 13:48, imeevma@tarantool.org wrote: > From: Kirill Yukhin > > This patch enables "autoindex" optimization. This optimization uses an > ephemeral space that contains all the fields used in the query. This Не очень понимаю, что значит "все поля в запросе"..? Это как?:) Ты имеешь ввиду все поля result-set'a? Или объединение всех полей всех таблиц используемых в запросе? > ephemeral space is called "autoindex". Autoindex may have fewer fields > than the original space, and the order of these fields in autoindex may Опять: original space - это какой спейс? В запросе может участвовать много таблиц.. Еще имхо какая-то путаница выходит: называем эфемерные спейсы автоиндексами. Я бы обозвал это как-нибудь по-другому. Это же просто еще одно использование эфемерных таблиц, не более. > be different from their order in the original space. In addition to the > mentioned fields, autoindex contains a rowid. > > The primary key of autoindex is a covering index, i.e. it contains all > of its fields. В мемтиксе все индексы покрывающие. И 'covering' - свойство для каждого запроса отдельно взятого, а не индекса как такового. > > Currently this optimization mainly used in cases when values SELECTED > from more than one space and WHERE specified. > > At the moment, this optimization does not take into account the number > of tuples in spaces. This should be fixed. > > Closes #4933 > > Co-authored-by: Mergen Imeev > Co-authored-by: Timur Safin > --- > https://github.com/tarantool/tarantool/issues/4933 > https://github.com/tarantool/tarantool/tree/imeevma/gh-4933-autoindex > > @ChangeLog > - "autoindex" optimization is now enabled (gh-4933). МНе кажется, можно чуть больше написать про такую важную штуку > src/box/CMakeLists.txt | 2 +- > src/box/sql.c | 2 +- > src/box/sql/delete.c | 28 ---- > src/box/sql/sqlInt.h | 35 ----- > src/box/sql/where.c | 238 +++++++++++++++++++++---------- > src/box/sql/wherecode.c | 13 +- > test/sql-tap/autoindex1.test.lua | 115 +++++++++++++++ > test/sql-tap/autoindex4.test.lua | 14 +- > test/sql-tap/whereF.test.lua | 16 ++- > test/sql/misc.result | 35 +++++ > test/sql/misc.test.lua | 14 ++ > 11 files changed, 358 insertions(+), 154 deletions(-) > create mode 100755 test/sql-tap/autoindex1.test.lua > > diff --git a/src/box/sql.c b/src/box/sql.c > index 000246ee9..a551bffc3 100644 > --- a/src/box/sql.c > +++ b/src/box/sql.c > @@ -719,7 +719,7 @@ int > tarantoolsqlIdxKeyCompare(struct BtCursor *cursor, > struct UnpackedRecord *unpacked) > { > - assert(cursor->curFlags & BTCF_TaCursor); > + assert(cursor->curFlags & (BTCF_TaCursor | BTCF_TEphemCursor)); > assert(cursor->iter != NULL); > assert(cursor->last_tuple != NULL); > > diff --git a/src/box/sql/where.c b/src/box/sql/where.c > index e9e936856..6ab2be3ba 100644 > --- a/src/box/sql/where.c > +++ b/src/box/sql/where.c > @@ -683,7 +683,6 @@ translateColumnToCopy(Vdbe * v, /* The VDBE containing code to translate */ > } > +/** > + * Generate a code that will create a tuple, which will be inserted in the > + * autoindex. The created tuple consists of rowid and fields described in the > + * index key description. > + * > + * @param parse Parsing context. > + * @param key_def The index key description. > + * @param cursor Cursor of space where we will get values for tuple. > + * @param reg_out Register to which the created tuple will be placed. > + * @param reg_eph Register holding pointer to autoindex. > + * > + * @return Return a register number which is the first in a block of registers > + * that holds the elements of the created tuple. The block of registers has > + * already been deallocated by the time this routine returns. Не очень понял, зачем возвращать уже деаллоцированные регистры.. > + */ > +static int > +vdbe_emit_create_autoindex_tuple(struct Parse *parse, > + const struct key_def *key_def, > + int cursor, int reg_out, int reg_eph) > +{ > + assert(reg_out != 0); > + struct Vdbe *v = parse->pVdbe; > + int col_cnt = key_def->part_count; > + int reg_base = sqlGetTempRange(parse, col_cnt + 1); > + for (int j = 0; j < col_cnt; j++) { > + uint32_t tabl_col = key_def->parts[j].fieldno; > + sqlVdbeAddOp3(v, OP_Column, cursor, tabl_col, reg_base + j); > + } > + sqlVdbeAddOp2(v, OP_NextIdEphemeral, reg_eph, reg_base + col_cnt); > + sqlVdbeAddOp3(v, OP_MakeRecord, reg_base, col_cnt + 1, reg_out); > + sqlReleaseTempRange(parse, reg_base, col_cnt + 1); > + return reg_base; > +} > + > /* > - * Generate code to construct the Index object for an automatic index > - * and to set up the WhereLevel object pLevel so that the code generator > - * makes use of the automatic index. > + * Generate code to construct the ephemeral space that contains all used in > + * query fields of one of the tables. This ephemeral space will be known as an Опять: какой таблицы..Очень запутывающий коммент имхо > + * "autoindex". PK of this ephemeral space is a covering index. Also, this > + * functions set up the WhereLevel object pLevel so that the code generator > + * makes use of the auto-index. > */ > static void > constructAutomaticIndex(Parse * pParse, /* The parsing context */ > } > * Estimate the location of a particular key among all keys in an > -#ifndef SQL_OMIT_AUTOMATIC_INDEX > /* Automatic indexes */ > - LogEst rSize = pTab->nRowLogEst; > + rSize = DEFAULT_TUPLE_LOG_COUNT; > + /* Increase cost of autoindex if number of tuples in space < ~10000. */ 10k как-то маловато. В скулайте, если я правильно помню, какие-то подвижки начинаются со 100к affected rows. > + if (!space->def->opts.is_view && sql_space_tuple_log_count(space) < 133) > + rSize += DEFAULT_TUPLE_LOG_COUNT; Почему для представления это не работает? > LogEst rLogSize = estLog(rSize); > if (!pBuilder->pOrSet && /* Not pqart of an OR optimization */ > (pWInfo->wctrlFlags & WHERE_OR_SUBCLAUSE) == 0 && > (pWInfo->pParse->sql_flags & SQL_AutoIndex) != 0 && > pSrc->pIBIndex == 0 /* Has no INDEXED BY clause */ > && !pSrc->fg.notIndexed /* Has no NOT INDEXED clause */ > &&!pSrc->fg.isCorrelated /* Not a correlated subquery */ > && !pSrc->fg.isRecursive /* Not a recursive common table expression. */ > ) { > @@ -2829,24 +2910,10 @@ tnt_error: > if (termCanDriveIndex(pTerm, pSrc, 0)) { > pNew->nEq = 1; > pNew->nSkip = 0; > - pNew->pIndex = 0; > + pNew->index_def = NULL; > pNew->nLTerm = 1; > pNew->aLTerm[0] = pTerm; > - /* TUNING: One-time cost for computing the automatic index is > - * estimated to be X*N*log2(N) where N is the number of rows in > - * the table being indexed and where X is 7 (LogEst=28) for normal > - * tables or 1.375 (LogEst=4) for views and subqueries. The value > - * of X is smaller for views and subqueries so that the query planner > - * will be more aggressive about generating automatic indexes for > - * those objects, since there is no opportunity to add schema > - * indexes on subqueries and views. > - */ > - pNew->rSetup = rLogSize + rSize + 4; > - if (!pTab->def->opts.is_view && > - pTab->def->id == 0) > - pNew->rSetup += 24; > - if (pNew->rSetup < 0) > - pNew->rSetup = 0; > + pNew->rSetup = rLogSize + rSize; Можешь объяснить, почему тут произошли изменения? То есть почему оптимизация стала более агрессивной? > /* TUNING: Each index lookup yields 20 rows in the table. This > * is more than the usual guess of 10 rows, since we have no way > * of knowing how selective the index will ultimately be. It would > diff --git a/src/box/sql/wherecode.c b/src/box/sql/wherecode.c > index 6d8768865..0d58b4701 100644 > --- a/src/box/sql/wherecode.c > +++ b/src/box/sql/wherecode.c > @@ -219,12 +219,12 @@ sqlWhereExplainOneScan(Parse * pParse, /* Parse context */ > > assert(!(flags & WHERE_AUTO_INDEX) > || (flags & WHERE_IDX_ONLY)); > - if (idx_def->iid == 0) { > + if ((flags & WHERE_AUTO_INDEX) != 0) { > + zFmt = "AUTOMATIC COVERING INDEX"; Я бы оставил просто automatic index > + } else if (idx_def->iid == 0) { > if (isSearch) { > zFmt = "PRIMARY KEY"; > } > - } else if (flags & WHERE_AUTO_INDEX) { > - zFmt = "AUTOMATIC COVERING INDEX"; > } else if (flags & WHERE_IDX_ONLY) { > zFmt = "COVERING INDEX %s"; > } else { > @@ -1047,8 +1048,6 @@ sqlWhereCodeOneLoopStart(WhereInfo * pWInfo, /* Complete information about the W > startEq = 0; > start_constraints = 1; > } > - struct index_def *idx_pk = space->index[0]->def; > - uint32_t pk_part_count = idx_pk->key_def->part_count; > /* > * Tarantool's iterator over integer fields doesn't > * tolerate floating point values. Hence, if term > @@ -1234,6 +1233,8 @@ sqlWhereCodeOneLoopStart(WhereInfo * pWInfo, /* Complete information about the W > if (omitTable) { > /* pIdx is a covering index. No need to access the main table. */ > } else if (iCur != iIdxCur) { > + struct index_def *idx_pk = space->index[0]->def; > + uint32_t pk_part_count = idx_pk->key_def->part_count; Этот дифф точно нужен для патча? > int iKeyReg = sqlGetTempRange(pParse, pk_part_count); > for (j = 0; j < (int) pk_part_count; j++) { > k = idx_pk->key_def->parts[j].fieldno; > diff --git a/test/sql-tap/autoindex1.test.lua b/test/sql-tap/autoindex1.test.lua > new file mode 100755 > index 000000000..42b995dd3 > --- /dev/null > +++ b/test/sql-tap/autoindex1.test.lua > @@ -0,0 +1,115 @@ > +#!/usr/bin/env tarantool > +test = require("sqltester") > +test:plan(7) > + > +-- 2010 April 07 > + > +-- The author disclaims copyright to this source code. In place of > +-- a legal notice, here is a blessing: > + > +-- May you do good and not evil. > +-- May you find forgiveness for yourself and forgive others. > +-- May you share freely, never taking more than you give. > + Необязательно включать эти странные хидеры в наши тесты.. > +--------------------------------------------------------------------------- > +-- This file implements regression tests for sql library. The focus of this > +-- script is testing automatic index creation logic. > + > +test:execsql([[ > + CREATE TABLE t1(a INT, b INT PRIMARY KEY); > + INSERT INTO t1 VALUES(1, 11); > + INSERT INTO t1 VALUES(2, 22); > + INSERT INTO t1 SELECT a + 2, b + 22 FROM t1; > + INSERT INTO t1 SELECT a + 4, b + 44 FROM t1; > + CREATE TABLE t2(c INT, d INT PRIMARY KEY); > +]]) > + > +for i = 1, 11000 do test:execsql("INSERT INTO t2 VALUES ("..i..", "..i..");") end Это быстро работает? Может сделать тест long-run? Было бы еще неплохо к каждой группе тестов коммент, поясняющий почему с эфмереной табличкой будет быстрее. > +test:do_execsql_test( > + "autoindex-1.1", [[ > + EXPLAIN QUERY PLAN SELECT b, (SELECT d FROM t2 WHERE c = a) FROM t1; > + ]], { > + 0,0,0,"SCAN TABLE T1 (~1048576 rows)", > + 0,0,0,"EXECUTE CORRELATED SCALAR SUBQUERY 1", > + 1,0,0,"SEARCH TABLE T2 USING AUTOMATIC COVERING INDEX (C=?) (~20 rows)" > + }) > + > +result = test:execsql([[SELECT b, (SELECT d FROM t2 WHERE c = a) FROM t1;]]) > + > +test:do_execsql_test( > + "autoindex-1.2", [[ > + EXPLAIN QUERY PLAN SELECT b, d FROM t1 JOIN t2 ON a = c ORDER BY b; > + ]], { > + 0,0,0,"SCAN TABLE T1 (~1048576 rows)", > + 0,1,1,"SEARCH TABLE T2 USING AUTOMATIC COVERING INDEX (C=?) (~20 rows)" > + }) > + > +test:do_execsql_test( > + "autoindex-1.3", [[ > + SELECT b, d FROM t1 JOIN t2 ON a = c ORDER BY b; > + ]], result) > + > +test:do_execsql_test( > + "autoindex-1.4", [[ > + EXPLAIN QUERY PLAN SELECT b, d FROM t1 CROSS JOIN t2 ON (c = a); > + ]], { > + 0,0,0,"SCAN TABLE T1 (~1048576 rows)", > + 0,1,1,"SEARCH TABLE T2 USING AUTOMATIC COVERING INDEX (C=?) (~20 rows)" > + }) > + > +test:do_execsql_test( > + "autoindex-1.5", [[ > + SELECT b, d FROM t1 CROSS JOIN t2 ON (c = a); > + ]], result) > + > +test:execsql([[ > + CREATE TABLE t3(i INT PRIMARY KEY, a INT, b INT); > +]]) > + > +for i = 1, 11000 do test:execsql("INSERT INTO t3 VALUES ("..i..", "..i..", "..(i + 1)..");") end > + > +test:do_execsql_test( > + "autoindex-1.6", [[ > + SELECT count(*) > + FROM t3 AS x1 > + JOIN t3 AS x2 ON x2.a=x1.b > + JOIN t3 AS x3 ON x3.a=x2.b > + JOIN t3 AS x4 ON x4.a=x3.b > + JOIN t3 AS x5 ON x5.a=x4.b > + JOIN t3 AS x6 ON x6.a=x5.b > + JOIN t3 AS x7 ON x7.a=x6.b > + JOIN t3 AS x8 ON x8.a=x7.b > + JOIN t3 AS x9 ON x9.a=x8.b > + JOIN t3 AS x10 ON x10.a=x9.b; > + ]], { > + 10991 > + }) > + > +test:do_execsql_test( > + "autoindex-1.7", [[ > + EXPLAIN QUERY PLAN SELECT count(*) > + FROM t3 AS x1 > + JOIN t3 AS x2 ON x2.a=x1.b > + JOIN t3 AS x3 ON x3.a=x2.b > + JOIN t3 AS x4 ON x4.a=x3.b > + JOIN t3 AS x5 ON x5.a=x4.b > + JOIN t3 AS x6 ON x6.a=x5.b > + JOIN t3 AS x7 ON x7.a=x6.b > + JOIN t3 AS x8 ON x8.a=x7.b > + JOIN t3 AS x9 ON x9.a=x8.b > + JOIN t3 AS x10 ON x10.a=x9.b; > + ]], { > + 0,0,0,"SCAN TABLE T3 AS X1 (~1048576 rows)", > + 0,1,1,"SEARCH TABLE T3 AS X2 USING AUTOMATIC COVERING INDEX (A=?) (~20 rows)", > + 0,2,2,"SEARCH TABLE T3 AS X3 USING AUTOMATIC COVERING INDEX (A=?) (~20 rows)", > + 0,3,3,"SEARCH TABLE T3 AS X4 USING AUTOMATIC COVERING INDEX (A=?) (~20 rows)", > + 0,4,4,"SEARCH TABLE T3 AS X5 USING AUTOMATIC COVERING INDEX (A=?) (~20 rows)", > + 0,5,5,"SEARCH TABLE T3 AS X6 USING AUTOMATIC COVERING INDEX (A=?) (~20 rows)", > + 0,6,6,"SEARCH TABLE T3 AS X7 USING AUTOMATIC COVERING INDEX (A=?) (~20 rows)", > + 0,7,7,"SEARCH TABLE T3 AS X8 USING AUTOMATIC COVERING INDEX (A=?) (~20 rows)", > + 0,8,8,"SEARCH TABLE T3 AS X9 USING AUTOMATIC COVERING INDEX (A=?) (~20 rows)", > + 0,9,9,"SEARCH TABLE T3 AS X10 USING AUTOMATIC COVERING INDEX (A=?) (~20 rows)" > + }) > + > +test:finish_test() > diff --git a/test/sql-tap/autoindex4.test.lua b/test/sql-tap/autoindex4.test.lua > index 46488f13a..e22f49c67 100755 > --- a/test/sql-tap/autoindex4.test.lua > +++ b/test/sql-tap/autoindex4.test.lua > @@ -1,6 +1,6 @@ > #!/usr/bin/env tarantool > test = require("sqltester") > -test:plan(7) > +test:plan(8) > > --!./tcltestrunner.lua > -- 2014-10-24 > @@ -75,6 +75,18 @@ test:do_execsql_test( > -- > }) > > +test:do_execsql_test( > + "autoindex4-2.0", > + [[ > + CREATE TABLE t3(i INT PRIMARY KEY, e INT, f INT); > + INSERT INTO t3 VALUES(1, 123,654), (2, 555,444), (3, 234,987); > + SELECT (SELECT count(*) FROM t1, t2 WHERE a=e AND x=f), e, f, '|' FROM t3 ORDER BY i; > + ]], { > + -- > + 1, 123, 654, "|", 0, 555, 444, "|", 4, 234, 987, "|" > + -- > + }) > + > -- do_execsql_test autoindex4-2.0 { > -- CREATE TABLE t3(e INT,f INT); > -- INSERT INTO t3 VALUES(123,654),(555,444),(234,987); > diff --git a/test/sql-tap/whereF.test.lua b/test/sql-tap/whereF.test.lua > index 5a894b748..3235df437 100755 > --- a/test/sql-tap/whereF.test.lua > +++ b/test/sql-tap/whereF.test.lua > @@ -90,10 +90,20 @@ test:do_execsql_test( > > -- for _ in X(0, "X!foreach", [=[["tn sql","\n 1 \"SELECT * FROM t1, t2 WHERE t1.a>? AND t2.d>t1.c AND t1.b=t2.e\"\n 2 \"SELECT * FROM t2, t1 WHERE t1.a>? AND t2.d>t1.c AND t1.b=t2.e\"\n 3 \"SELECT * FROM t2 CROSS JOIN t1 WHERE t1.a>? AND t2.d>t1.c AND t1.b=t2.e\"\n"]]=]) do > for tn, sql in ipairs({"SELECT * FROM t1, t2 WHERE t1.a>? AND t2.d>t1.c AND t1.b=t2.e", > - "SELECT * FROM t2, t1 WHERE t1.a>? AND t2.d>t1.c AND t1.b=t2.e", > - "SELECT * FROM t2 CROSS JOIN t1 WHERE t1.a>? AND t2.d>t1.c AND t1.b=t2.e"}) do > + "SELECT * FROM t2, t1 WHERE t1.a>? AND t2.d>t1.c AND t1.b=t2.e"}) do > test:do_test( > - "2."..tn, > + "2.1."..tn, > + function() > + return test:execsql("EXPLAIN QUERY PLAN "..sql) > + end, { > + '/SEARCH TABLE T1/', > + '/SEARCH TABLE T2/' > + }) > +end > + > +for tn, sql in ipairs({"SELECT * FROM t2 CROSS JOIN t1 WHERE t1.a>? AND t2.d>t1.c AND t1.b=t2.e"}) do > + test:do_test( > + "2.2."..tn, > function() > return test:execsql("EXPLAIN QUERY PLAN "..sql) > end, { > diff --git a/test/sql/misc.result b/test/sql/misc.result > index 6af11bfba..b52a83bda 100644 > --- a/test/sql/misc.result > +++ b/test/sql/misc.result > @@ -204,3 +204,38 @@ box.execute('SELECT field66, field68, field70 FROM test') > box.space.TEST:drop() > --- > ... > +-- gh-4933: Make sure that autoindex optimization is used. > +box.execute('CREATE TABLE t1(i INT PRIMARY KEY, a INT);') > +--- > +- row_count: 1 > +... > +box.execute('CREATE TABLE t2(i INT PRIMARY KEY, b INT);') > +--- > +- row_count: 1 > +... > +for i = 1, 11000 do\ > + box.execute('INSERT INTO t1 VALUES ($1, $1);', {i})\ > + box.execute('INSERT INTO t2 VALUES ($1, $1);', {i})\ > +end > +--- > +... > +-- > +-- There is no need to insert values in the tables since planner assumes a > +-- default number of tuples for each space, regardless of how many tuples there > +-- actually are in those spaces. The default value is 1048576 (== 2^20). > +-- > +box.execute('EXPLAIN QUERY PLAN SELECT a, b FROM t1, t2 WHERE a = b;') > +--- > +- metadata: > + - name: selectid > + type: integer > + - name: order > + type: integer > + - name: from > + type: integer > + - name: detail > + type: text > + rows: > + - [0, 0, 0, 'SCAN TABLE T1 (~1048576 rows)'] > + - [0, 1, 1, 'SEARCH TABLE T2 USING AUTOMATIC COVERING INDEX (B=?) (~20 rows)'] > +... > diff --git a/test/sql/misc.test.lua b/test/sql/misc.test.lua > index 63244228c..d7673bb49 100644 > --- a/test/sql/misc.test.lua > +++ b/test/sql/misc.test.lua > @@ -64,3 +64,17 @@ box.execute('SELECT field70, field64 FROM test') > pk:alter({parts = {66}}) > box.execute('SELECT field66, field68, field70 FROM test') > box.space.TEST:drop() > + > +-- gh-4933: Make sure that autoindex optimization is used. > +box.execute('CREATE TABLE t1(i INT PRIMARY KEY, a INT);') > +box.execute('CREATE TABLE t2(i INT PRIMARY KEY, b INT);') > +for i = 1, 11000 do\ > + box.execute('INSERT INTO t1 VALUES ($1, $1);', {i})\ > + box.execute('INSERT INTO t2 VALUES ($1, $1);', {i})\ > +end > +-- > +-- There is no need to insert values in the tables since planner assumes a > +-- default number of tuples for each space, regardless of how many tuples there > +-- actually are in those spaces. The default value is 1048576 (== 2^20). > +-- > +box.execute('EXPLAIN QUERY PLAN SELECT a, b FROM t1, t2 WHERE a = b;') > -- > 2.25.1 >